Porphyrins

Vanadyl etioporphyrin I has C4 symmetry and is chiral. Hence,
it should be resolvable. Attempts were made to resolve it into its
enantiomers by chromatography using optically active ads or bents since
it has no functional groups which can be used to form isolable
diastereomers. Numerous optically active ads or bents were tried in the
pure state and adsorbed on silica gel. In most cases the Rf values were
either close to zero or close to one, making resolution impossible. Only
in the case of lactose on silica gel and using benzene as the solvent was
the Rf value such (approx. 0. 52) that resolution seemed, at least, possible.
However, no optically active fraction could be obtained on column
chromatography. Since oxygen exchange between the vanadyl group of vanadyl
etioporphyrin I and water might occur and cause rapid interconversion
of the enantiomers (hence racemization), thereby vitiating resolution
attempts, the possibility of such oxygen exchange was investigated under
a variety of conditions by means of H2 O^18 . The I. R. method was used to
detect any such exchange (VO^18 vs. VO^16). It was found that vanadyl etioporphyrin
I fails to undergo any measurable exchange under all the conditions
tried, although the vanadyl ion of vanadyl sulfate does undergo
exchange.

A method of reversed phase HPLC gradient elution was developed and evaluated for the separation of vanadyl porphyrins. Separation was compared with the result of isocratic elution. It shows that gradient elution method is suitable for vanadyl porphyrin separation and better separation result can be obtained by gradient elution. Gradient elution improves the separation by changing the retention time of different components in the sample mixture and increases the difference of k' (capacity factor). Vanadyl porphyrin samples Bakken 6362', Treibs #1 and Treibs #3 were analyzed by this method. Results correlate very well with the results of mass spectrometry analysis of these samples which have been done by some other workers.

New organometallic containing materials were synthesized by the reaction of Group IVB metallocene dichlorides of the form Cp2MCl2 where M = Ti, Ar, and Hf with Hematoporphyrin IX using the interfacial condensation polymerization technique. The structural characterization was accomplished using infrared and mass spectroscopy and elemental analysis. The results obtained from these techniques showed the presence of the metal ester and ether bonding as evidence that the reaction occurred. The product derived from titanocene dichloride, 12-A, exhibited growth inhibition characteristics towards the Candid albicans and Staphylococcus aureus microorganisms. From the preliminary metal adsorption studies it was shown that this product also bound nickel ions.

HPLC separation of nickel geoporphyrin homologues and isomers has been markedly enhanced by a number of modifications of previously disclosed methods. A general, more efficient and reproducible method has been developed. A C18 3-micron reverse phase column with a programmed gradient binary mobile phase composed of solvent A which is methanol, water and solvent B which consists of methanol modified by the addition of powerful ligand; a consistent ratio of organic salt is added into this solvent system to increase ionic strength of mobile phase. Straightforward HPLC separations of some marine sediment and oil shale extracts (nickel porphyrins) without demetallation have been successfully achieved. Most attention has been focused on Cowboy Gilsonite and Bakken oil-shale. Individual fractions have been collected and analyzed by UV-VIS, NMR, Mass spectrometry. Known compounds were used for co-chromatographic and spectroscopic reference.

The ensuing treatise details the routes investigated in the
attempt to synthesize a novel porphyrin related to
deoxophylloerythroetioporphyrin (DPEP), containing a fused
six-membered cycloalkano ring system and a carboxylic acid
chain in its structure. Mesorhodin methyl ester, the
intermediate used throughout this study was obtained from
mesoporphyrin dimethyl ester which in turn, was prepared
from hemin.
Attempts to reduce the keto-function in mesorhodin methyl
ester to the corresponding methylene group in our target
coumpound were based on two methods. The first approach
was application of the Huang-Minlon modification of the
Wolff-Kischner reaction. The second procedure considered
chemical and catalytic hydrogenations as well as
dehydration reactions. Although our proposed pathways were
found to be unsatisfactory, the latter methodology did lead
to unreported intermediates and a new porphyrin with a
fused benzene ring. Their syntheses and spectral properties
are discussed.